Large circuit breakers that carry thousands of amps of current are oftentimes installed into metal-enclosed switchgear assemblies (also called “switchboards”). Switchgears have large electrical conductors called bus bars (sometimes referred to as “buss bars”) that carry current from a power source, such as a power utility, through the circuit breakers, to loads that are protected by the circuit breaker. These large circuit breakers, which can weigh hundreds of pounds, are typically lifted into the switchgear and racked by mounting the circuit breakers into a drawout cradle. A manually controlled or remotely operated handle mechanism is inserted into the cradle to turn a crank that racks the circuit breaker into the switchgear and completes an electrical circuit which is protected by the breaker.
On the backs of these large circuit breakers facing the rear interior of the switchgear cabinet are connection members, such as bus bars, with pivots (also known as “cluster supports”) that jut out like rails on a train track. Onto these pivots are installed multiple “clusters,” which are connectors that have opposing stacks of plate-like fingers that straddle the pivots and allow the clusters to adapt their positions to engage bus bars in the switchgear cabinets during the blind rack-in connection. These fingers are biased by spring elements to stay on the pivots so that the cluster “snaps” onto the pivot. It is important that these clusters remain secured on the pivots because if they become loose or dislodged as the circuit breaker is being racked into the switchgear or during operation of the switchgear, a dangerous cross-phase connection or a short circuit from an electrical phase to ground can occur, which can result in an explosive electrical arc.
Heretofore, various prior art approaches have been proposed for securing clusters to the pivots. For example, one current approach requires fastening the clusters to the pivots using a U-shaped retainer pin and a retainer clip. Another current approach requires securing a cage around a group of clusters to anchor them onto the pivots. These approaches for securing clusters to the pivots undesirably require additional installation time and labor due to additional parts and/or additional installation steps. What is needed is a solution that securely and reliably holds the clusters onto their pivots with minimal complexity, fewer parts, and reduced labor costs.